<!doctype html>
<html>
<head>
    <meta charset="utf-8">
    <title>Random Flow - ECHARTS-GL</title>
    <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
    <meta name="apple-mobile-web-app-capable" content="yes"> <!-- Fullscreen Landscape on iOS -->
    <link rel="stylesheet" href="./common.css">
</head>
<body>
<div id="main"></div>
<script src="../node_modules/echarts/dist/echarts.js"></script>
<script src="../dist/echarts-gl.js"></script>
<script src="lib/jquery.min.js"></script>
<script src="lib/simplex.js"></script>
<script src="js/commonUI.js"></script>
<script>
    var chart = echarts.init(document.getElementById('main'));

    var noise = new SimplexNoise(Math.random);
    var noise2 = new SimplexNoise(Math.random);

    function generateData() {
        var data = [];
        for (var i = 0; i <= 50; i++) {
            for (var j = 0; j <= 50; j++) {
                var dx = noise.noise2D(i / 30, j / 30);
                var dy = noise2.noise2D(i / 30, j / 30);
                var mag = Math.sqrt(dx * dx + dy * dy);
                valMax = Math.max(valMax, mag);
                valMin = Math.min(valMin, mag);
                data.push([i, j, dx, dy, mag]);
            }
        }
        return data;
    }

    var valMin = Infinity;
    var valMax = -Infinity;
    var data = generateData();

    chart.setOption({
        visualMap: {
            show: false,
            min: valMin,
            max: valMax,
            dimension: 4,
            inRange: {
                color: ['#313695', '#4575b4', '#74add1', '#abd9e9', '#e0f3f8', '#ffffbf', '#fee090', '#fdae61', '#f46d43', '#d73027', '#a50026']
            }
        },
        xAxis: {
            type: 'value',
            axisLine: {
                lineStyle: {
                    color: '#fff'
                }
            },
            splitLine: {
                show: false,
                lineStyle: {
                    color: 'rgba(255,255,255,0.2)'
                }
            }
        },
        yAxis: {
            type: 'value',
            axisLine: {
                lineStyle: {
                    color: '#fff'
                }
            },
            splitLine: {
                show: false,
                lineStyle: {
                    color: 'rgba(255,255,255,0.2)'
                }
            }
        },
        series: [{
            type: 'flowGL',
            data: data,
            particleDensity: 64,
            particleSize: 5,
            itemStyle: {
                opacity: 0.5
            }
        }, {
            type: 'custom',
            data: data,
            encode: {
                x: 0,
                y: 0
            },
            renderItem: function (params, api) {
                var x = api.value(0), y = api.value(1), dx = api.value(2), dy = api.value(3);
                var start = api.coord([x - dx / 2, y - dy / 2]);
                var end = api.coord([x + dx / 2, y + dy / 2]);
                return {
                    type: 'line',
                    shape: {
                        x1: start[0], y1: start[1],
                        x2: end[0], y2: end[1]
                    },
                    style: {
                        lineWidth: 2,
                        stroke: '#fff'
                    }
                }
            }
        }]
    });

    window.onresize = chart.resize;
</script>
</body>
</html>
